Factory Acceptance Test Checklist for Custom Machinery Builders

Write the Protocol Before You Build

The FAT protocol should be agreed during the quote or design approval phase, not the week before the customer arrives. Derive it from the specification: each performance requirement becomes a test. Throughput is run for a defined duration with a count, accuracy is measured with agreed gauges on a defined sample size, changeover is timed, and safety functions such as e-stops, guard interlocks, and light curtains are verified individually.

Attach the protocol to the contract so both sides know what pass means. If the customer proposes extra tests later, treat them as a change order.

• One test per requirement with a numeric criterion
• Defined sample size, run duration, and measuring method
• Safety function verification list
• Who supplies the test parts and by when

Test Samples and Customer Inputs

The most common FAT delay is missing or wrong product. Specify the quantity, material lot, and condition of customer-supplied samples, and set a delivery date as a customer assumption. Include good parts and known-bad parts for inspection systems so detection is demonstrated.

For machines that process variants, plan how many variants to run during the FAT. Agree on what happens if the samples are out of tolerance, since that is the customer's issue and not a machine failure.

Run Your Own Pre-FAT

Do an internal run, called a dry or pre-FAT, one to two weeks earlier, using the same protocol and the customer's samples if you have them. Record failures, fix them, and re-run. Customers form their impression within the first hour of FAT.

A pre-FAT also gives accurate data for scheduling shipment and freight. Capture cycle times, reject rates, and downtime reasons because they become baseline evidence and help sort warranty claims later.

Punch List, Sign-Off, and Billing

During the FAT, log every observation with a category: failure against specification, improvement request, or documentation. Only items in the first category block acceptance. Agree on a punch list with owners and dates, and define which items must close before shipment versus at site acceptance.

The signed FAT report, with test data attached, usually triggers a payment milestone, so tie it into your ERP billing events. Store the report with the project record, with the as-built drawings and software backup, because the same file supports service calls years later.

Using Data From Past FATs

Past FAT reports hold knowledge: which requirements fail most often, how many rounds were needed, how long they took. A private AI layer over those reports can suggest tests and likely failure points for a new machine of a similar type and flag a customer requirement that has failed first time before. It reads documents, it does not run the test.

If you build one repeating product line, a locked FAT template is more valuable than anything AI could add.